This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study will evaluate different methods of processing equine (horse) tendon and chondroplug (a piece of bone with cartilage attached) with the ultimate goal of using them for human transplantation. The processing of the tissue is designed to reduce the amount of substances that might cause rejection or reaction in a human. A small piece of treated tendon or chondroplug will be implanted under the skin on the back of the baboon and left for 30 days. After 30days, the implants, plus some surrounding tissue, will be removed and graft acceptance/rejection will be evaluated by a pathologist. The outcome of these studies will provide valuable information about the efficacy of processing to make the transplant acceptable for human use.